A communication device is a device provided with appropriate communication and control capabilities for enabling use thereof for communication with others devices. The communication typically is provided with an interface for accessing a communication system which carries the communication to and from the communication device. A communications system is thus a facility which enables communication between two or more remote entities such as communication device, network entities and other nodes. The communication may comprise, for example, communication of voice, electronic mail (email), text messages, data, multimedia and so on. The communication device may comprise any device facilitating sending and/or receiving communication, for example an appropriate user equipment (mobile or fixed), a mobile station and so on.
An appropriate access system typically provides a user with an access to the communications system. An access system typically operates in accordance with a given standard or with a given set of specifications which set out what the various elements of the system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely user equipment, is provided with a circuit switched bearer or a packet switched bearer, or both. Communication protocols and/or parameters which should be used for the connection are also typically defined. For example, the manner in which communication should be implemented between the user equipment and the elements of the networks is typically based on a predefined communication protocol.
An access to a communications network may be provided by a fixed or wireless communication interface. Communication systems providing wireless access typically enable at least some degree of mobility for the users thereof. That is, the user may roam within the service area of his home network from an access area to another access area. The users are also typically allowed to roam into other networks, thus enabling use of the communication device even when the user is not located within the service are of his/hers home network but is visiting another network.
An example of a communication network providing wireless access and mobility is a public land mobile network (PLMN), such as the second generation (2G) GSM (Global System for Mobile communications), the so called third generation (3G) GPRS (General Packet Radio Service), and/or the WCDMA (Wideband Code Division Multiple Access) or EDGE (Enhanced Data for GSM Evolution) and so forth. Other examples of wireless access technologies include various different wireless local area networks (WLANs), Wi-Fi networks and satellite based communication systems.
The public land mobile networks (PLMN) are commonly based on cellular technology. In cellular systems, a base transceiver station (BTS) or similar entity providing an access area services a mobile communication device via a wireless interface. The operation of the base station apparatus and other apparatus required for the operation of the access system can be controlled by one or several control entities. An access area such as a cell can only serve a limited geographical area and also a limited number of users, and therefore a mechanism known as a handover is developed enabling the mobile device to move from an access area to another.
A mobile communication device may be configured to be compatible with different access technologies and thus capable of communication via a plurality of different access systems. For example, a mobile device may be provided with multi-radio capabilities, thus enabling access to services via a plurality of different radio access networks and a handover there between.
As mentioned above, a communication system such as a cellular communication system comprises a plurality of access areas. Neighbouring access areas typically overlap to ensure continuous coverage instead of just being next to each other, as illustrated in FIG. 1. The network typically maintains for each access area a defined set of available other access areas. In certain standards, the set of available access areas is termed a neighbour cell list (NCL). The mobile device may be handed over from an access area to another access area assuming that the other access area is on the set of available access areas. These sets are typically communicated to the mobile devices so that they are aware of the available access areas. In a normal mode the mobile device only cares about access areas that were included in the set of available areas. If it is detected that a detected access is not included in the set of available access areas, the mobile device typically takes no action. However, if a feature such as detected set reporting (DSR) or similar is activated, the mobile can monitor other access areas than those described in the set of access areas it received from the network.
The sets of access areas are an important management tool for the operators in providing continuous mobility and good quality service and therefore a lot of effort is put into maintaining a list of neighbour cells for each cell or similar sets. The sets of access areas are typically created at the time of building a network. The sets of access areas may be updated from time to time.
Identifying and adding missing neighbours to the sets is a particular aspect of the management. The term missing neighbour refers to a cell or another access area that is not defined in a set of available access area, for example a neighbour list but nevertheless provides good radio conditions within a particular access area. Managing a neighbour list for an access area thus includes identifying and adding potential missing neighbours that are not yet, for reason or another, defined in the neighbour list. When managing a neighbour list, a set of missing neighbours can be detected or found based on information such as coverage predictions, field measurements and so on. In the existing systems all identified missing neighbours are added to the neighbour list. The operator may then later on delete those neighbours from the list that do not perform especially well, and thus do not function as “good neighbours” for the particular access area.
The performance of the added neighbours, however, can only be evaluated later on, after the operator has gained some experience of this. Those missing neighbours that are considered as ones that do not contribute to an improvement on the performance can then be deleted from the neighbour list.
The automatic inclusion of all identified missing neighbours into the neighbour list may not be an optimal solution in certain occasions. For example, the size of the list may be such that not all of the identified missing neighbours will necessary fit into the neighbour list. Also, not all of the identified missing neighbours may actually be good neighbours, and thus this may result in unnecessarily adding neighbours into the neighbour list, which then need to be removed later on by the operators.